#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int arr[10] = { 1,2,3,4,5,6,7,8,9,10 };
	int a = 0;
	scanf("%d", &a);
	int left = 0;
	int right = 9;
	int b = 0;
	int c = 1;
	while (left <= right)
	{
		 b = (left + right) / 2;
		if (arr[b] < a)
		{
			left = b + 1;
		}
		if (arr[b] > a)
		{
			right = b - 1;
		}
		if (arr[b] == a)
		{
			printf("yes");
			c = 0;
			break;
		}
		
	}
	if (c)
	{
		printf("no");
	}
	

	return 0;
}